JP2011148629A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus preventing the occurrence of a paper feeding jam in the image forming apparatus including a plurality of paper feeding trays and constituted such that a part of a paper conveying path supplied with paper from the paper feeding tray in a lower stage is formed inside the body paper feeding tray in an upper stage. <P>SOLUTION: A printer 100 includes four paper feeding parts (a first paper feeding cassette 91, a second paper feeding tray 92a, a third paper feeding tray 92b and a fourth paper feeding tray 92c), and conveying paths 11, 12a-12c heading toward a conveying path 13 from the respective paper feeding trays. The conveying paths 12a-12c are constituted to respectively pass via the paper feeding tray in the upper stage. In such a constitution, when there are a plurality of paper feeding trays that can feed paper, the paper is fed preferentially from the paper feeding tray in the lower stage. The upper stage tray is not thereby pulled out to replenish a recording medium to the empty paper feeding tray in the upper stage, and the occurrence of the paper feeding jam can be prevented. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus including a plurality of paper feed trays.

  Conventionally, an image forming apparatus including a plurality of paper feed trays has been disclosed. For example, Patent Document 1 discloses an image forming apparatus in which a paper feed tray is provided at the bottom of the main body of the image forming apparatus, and a paper feed tray can be added below the main body paper feed tray. Further, in the image forming apparatus described in Document 1, a part of the sheet conveyance path for conveying the sheet fed from the lower additional sheet feeding tray to the image forming unit is provided inside the upper body sheet feeding tray. Is formed.

JP 2006-96456 A

  However, the image forming apparatus described in Patent Document 1 has the following problems. For example, the image forming apparatus disclosed in Patent Document 1 is configured to block the sheet conveyance path of the additional paper feed tray located in the lower stage when the main body paper feed tray located in the upper stage is pulled out. As a result, when the user pulls out the main unit paper tray while the additional paper tray is feeding, if the user pulls out the main unit paper tray, a paper jam will occur in the additional paper tray and printing will fail. It will be interrupted.

  The present invention has been made to solve the problems of the above-described conventional print forming apparatus and paper feed control method. That is, an object of the present invention is to provide an image forming apparatus that includes a plurality of paper feed trays and a part of a paper transport path that feeds paper from a lower paper feed tray is formed inside an upper main body paper feed tray. An object of the present invention is to provide an image forming apparatus that prevents the occurrence of paper jam.

  The image forming apparatus according to claim 1 of the present invention, which has been made for the purpose of solving this problem, is disposed above and below the image forming means for printing an image on a recording medium and the recording medium. A plurality of paper feed trays, a print path for transporting the recording medium to the image forming unit, a first paper feed path for transporting the recording medium from the uppermost paper feed tray to the print path, A second paper feed path for transporting the recording medium ejected from the paper feed trays excluding the upper paper feed tray to the print path via the paper feed tray above the paper feed tray; A sheet feeding unit configured to feed the recording medium stored in one of the sheet feeding trays, and the sheet feeding unit includes a plurality of sheet feeding trays capable of feeding toward the image forming unit; Of the multiple paper trays, the lower Characterized by feeding paper from the tray. That is, by feeding the lower feed tray preferentially, the recording medium is emptied from the lower feed tray. Therefore, it is possible to prevent the upper tray from becoming empty from the paper feed tray that is feeding paper. With this configuration, the possibility that the upper paper feed tray is pulled out to replenish the recording medium to the empty upper paper feed tray is reduced, and the occurrence of paper jam can be prevented. Note that since the recording medium is replenished to the lower paper feed tray than the paper feed tray that is feeding paper, the paper feed path is not interrupted even when the user pulls out the lower paper feed tray. Therefore, it is possible to prevent a paper jam from occurring due to the replenishment of paper to the paper feed tray.

  An image forming apparatus according to a second aspect of the present invention is the image forming apparatus according to the first aspect, wherein the presence / absence detection of a sheet for detecting the presence / absence of the recording medium stored in the sheet feeding tray is performed. And when the sheet presence / absence detecting unit detects that there is no recording medium stored in the sheet feeding tray being fed, the sheet feeding unit is provided at a level above the sheet feeding tray. It is characterized in that the paper feed is continued by switching to the paper feed tray. That is, during paper feeding, even if the paper feeding tray becomes empty, the upper paper feeding tray is automatically switched, so that printing can be continued. In addition, it is possible to prevent the upper paper feed tray from becoming empty relative to the paper feed tray that is currently feeding paper, so that the occurrence of paper jam can be prevented. Note that since the recording medium is replenished to the empty lower paper feed tray, even if the user pulls out the lower paper feed tray, the paper feed path is not interrupted. It is possible to prevent the occurrence of paper jam due to the replenishment of paper.

  An image forming apparatus according to a third aspect of the present invention is the image forming apparatus according to the first or second aspect, wherein the presence or absence of the recording medium stored in the paper feed tray is detected. A paper feed tray that does not have the plurality of recording media when the paper presence / absence detection means detects that the recording media are not present in the plurality of paper feeding trays. Among these, paper is fed from the upper paper feed tray than the uppermost paper feed tray. In other words, by feeding the upper paper feed tray above the uppermost paper feed tray among the empty paper feed trays, it is possible to avoid the upper paper feed tray from being empty. Thus, it is possible to prevent a paper jam from occurring due to paper replenishment to the paper feed tray.

  An image forming apparatus according to a fourth aspect of the present invention is the image forming apparatus according to any one of the first to third aspects, wherein the paper feeding unit is in order from the lower paper feeding tray. It is characterized by feeding paper. In other words, by feeding the lower feed tray preferentially, it is possible to avoid emptying the upper feed tray from the paper feed tray being fed, and to feed the paper by refilling the paper feed tray. Can be prevented.

  An image forming apparatus according to a fifth aspect of the present invention is the image forming apparatus according to any one of the second to fourth aspects, wherein the paper feeding unit is fed by the paper presence / absence detecting unit. When it is detected that the recording medium stored in the paper tray is not present, the paper feed tray is removed from the switching target and is set as a waiting for replenishment, and the recording medium is detected by the paper presence detecting means. In this case, the paper feed tray is a switching target. That is, when a recording medium is replenished to an empty paper feed tray, printing can be continued by switching to the replenished paper feed tray and feeding again.

  An image forming apparatus according to a sixth aspect of the present invention is the image forming apparatus according to the fifth aspect, wherein warning means for issuing a warning prompting replenishment of the recording medium to the paper supply tray waiting for replenishment is provided. The warning means outputs the warning in order from the upper paper feed tray among the paper feed trays waiting for replenishment. With this configuration, printing can be continued by prompting the replenishment of the recording medium before all the paper feed trays are emptied. In addition, since the warning means issues warnings in order from the upper paper feed tray among the paper feed trays waiting to be replenished, the upper tray with respect to the paper feed tray to be fed is prevented from becoming empty. A paper feed tray supplemented with a recording medium can be a switching target. Thereby, it is possible to continue printing while preventing the occurrence of paper jam.

An image forming apparatus according to claim 7 of the present invention includes an image forming unit that prints an image on a recording medium, and a plurality of paper feed trays that are arranged above and below to accommodate the recording medium, A main paper feed path for transporting the recording medium discharged from the paper feed tray to the image forming unit and a paper feed tray other than the lowermost paper feed tray, and a lower stage of the paper feed tray A sub paper feed path for guiding the recording medium discharged from the paper feeding tray toward the main paper feeding path, and the recording medium accommodated in one of the plurality of paper feeding trays. A sheet feeding unit for feeding paper is provided, and the sheet feeding unit feeds paper from a lower sheet feeding tray when there are a plurality of sheet feeding trays capable of feeding toward the image forming unit. That is, by feeding the lower feed tray preferentially, the recording medium is emptied from the lower feed tray. Therefore, it is possible to prevent the upper tray from becoming empty from the paper feed tray that is feeding paper. With this configuration, the possibility that the upper paper feed tray is pulled out to replenish the recording medium to the empty upper paper feed tray is reduced, and the occurrence of paper jam can be prevented. Note that since the recording medium is replenished to the lower paper feed tray than the paper feed tray that is feeding paper, the paper feed path is not interrupted even when the user pulls out the lower paper feed tray. Therefore, it is possible to prevent a paper jam from occurring due to the replenishment of paper to the paper feed tray.

  According to the present invention, in an image forming apparatus that includes a plurality of paper feed trays and a part of a paper transport path for feeding paper from a lower paper feed tray is formed inside an upper main body paper feed tray. An image forming apparatus that prevents the occurrence of paper jam is realized.

1 is a perspective view illustrating a schematic configuration of an image forming apparatus according to an embodiment. FIG. 2 is a conceptual diagram illustrating an internal configuration of an image forming unit according to the image forming apparatus of FIG. 1. FIG. 2 is a block diagram illustrating an electrical configuration of the image forming apparatus in FIG. 1. 6 is a flowchart illustrating print job execution processing according to the embodiment. It is a flowchart which shows the priority change necessity determination process concerning embodiment. It is a flowchart which shows the priority change process concerning embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[Entire printer configuration]
FIG. 1 is a perspective view illustrating a schematic configuration of a printer 100 (image forming apparatus) according to the present embodiment. The printer 100 includes an image forming unit 10 that prints an image on a sheet (recording medium), a paper feed tray 91 (hereinafter referred to as a first paper feed tray 91) located at the bottom of the image forming unit 10, and an image forming unit. 10 is provided with a paper discharge tray 93 positioned on the upper surface of the apparatus 10. In the printer 100, optional trays 92a to 92c (hereinafter, the optional trays 92a to 92c are referred to as a second paper feed tray 92a, a third paper feed tray 92b, and a fourth paper feed tray 92c, respectively) below the paper feed tray 91 are optional. It can be expanded with.

  Further, on the upper surface of the image forming unit 10, an operation panel 40 including a display unit 41 formed of a liquid crystal display, a button group 42 including various buttons (for example, buttons of a start key, a stop key, and a numeric keypad). Is provided. The display unit 41 and the button group 42 enable operation status display and user operation input.

[Configuration of image forming unit]
FIG. 2 is a conceptual diagram illustrating an internal configuration of the image forming unit 10 of the printer 100. The image forming unit 10 forms an image by a known electrophotographic method. As shown in FIG. 2, the image forming unit 10 forms a process unit 50 for forming an image, a fixing device 8 for fixing an unfixed toner image, and an image. A first paper feed tray 91, a second paper feed tray 92a, a third paper feed tray 92b, and a fourth paper feed tray 92c for placing paper before formation, and a paper discharge tray 93 for placing paper after image formation. And.

  In the image forming unit 10, the paper stored in the first paper feed tray 91 passes through the paper feed roller 71, the registration roller 75, the process unit 50, and the fixing device 8, and is discharged through the paper discharge roller 73. A substantially S-shaped conveyance path (a chain line in FIG. 2) is provided so as to be guided to the paper tray 93. That is, the image forming unit 10 takes out the sheets placed on the first paper feed tray 91 one by one, conveys the sheets to the process unit 50, and displays the toner image formed in the process unit 50 on the sheet. Transcript to. Further, the sheet on which the toner image is transferred is conveyed to the fixing device 8 and the toner image is thermally fixed on the sheet. Then, the paper after fixing is discharged to the paper discharge tray 93. Of the substantially S-shaped transport path, the transport path 11 (first paper feed path, main paper feed path) is a path from the first paper feed tray 91 to the registration roller 75, and the paper discharge tray 93 from the registration roller 75. Up to the transport path 13 (printing pass).

  Further, in the image forming unit 10, the paper stored in the second paper feed tray 92 a located below the first paper feed tray 91 passes through the paper feed roller 72 a in the paper transport direction more than the registration roller 75. A transport path 12a (second feed path, sub-feed path, two-dot chain line in FIG. 2) that joins the transport path 11 is provided on the upstream side. That is, when the image forming unit 10 feeds paper from the second paper feed tray 92 a, the image forming unit 10 conveys the paper taken out from the second paper feed tray 92 a to the registration roller 75 via the first paper feed tray 91.

  The sheet accommodated in the third sheet feed tray 92b positioned below the second sheet feed tray 92a passes through the sheet feed roller 72b and joins the transport path 11 upstream of the registration roller 75 in the sheet transport direction. A path 12b (second paper feed path, two-dot chain line in FIG. 2) is provided. That is, when the image forming unit 10 feeds paper from the third paper feed tray 92b, the image forming unit 10 registers the paper taken out from the third paper feed tray 92b via the first paper feed tray 91 and the second paper feed tray 92a. Transport to roller 75. Here, the transport path 12b (sub-paper feed path) may join the transport path 12a (main paper feed path) upstream of the registration rollers 75 in the paper transport direction.

  The sheet accommodated in the fourth sheet feed tray 92c positioned below the third sheet feed tray 92a passes through the sheet feed roller 72c and joins the transport path 11 on the upstream side of the registration roller 75 in the sheet transport direction. A path 12c (second feed path, two-dot chain line in FIG. 2) is provided. That is, when the image forming unit 10 feeds paper from the fourth paper feed tray 92c, the first paper feed tray 91, the second paper feed tray 92a, and the third paper feed are taken out from the fourth paper feed tray 92c. It is conveyed to the registration roller 75 via the tray 92b. Here, the transport path 12c (sub-paper feed path) may join the transport path 12b (main paper feed path) upstream of the registration rollers 75 in the paper transport direction.

  Therefore, as described above, the first paper feed tray 91 includes a part of the three transport paths, that is, the transport paths 12a to 12c, and the second paper feed tray 92a includes the transport paths 12b and 12c. A part of the two transport paths exists, a part of the transport path 12c exists in the third paper feed tray 92b, and a transport path does not exist in the fourth paper feed tray 92c.

  Because of the above configuration, for example, the paper transport path 12 a from the second paper feed tray 92 a is formed via the first paper feed tray 91. Therefore, when the user removes the first paper feed tray 91 from the apparatus main body in order to replenish paper in the first paper feed tray 91 during paper feed from the second paper feed tray 92a, the transport path 12a is blocked and transported. It becomes impossible. Therefore, if the first paper feed tray 91 is taken out while paper is being fed from the second paper feed tray 92a, it is not preferable because it causes a paper feed jam.

The process unit 50 includes a process unit 50C that forms a cyan (C) image, a process unit 50M that forms a magenta (M) image, and a process unit 50Y that forms a yellow (Y) image. And a process unit 50K that forms a black (K) color image, and the process units 50C, 50M, 50Y, and 50K are juxtaposed along a paper conveyance path. The process unit 50 forms a color image by superimposing the toner images formed by the process units 50C, 50M, 50Y, and 50K on a sheet. On the other hand, when a monochrome image is formed, a toner image is formed and printed by any one of the process units 50C, 50M, 50Y, and 50K.

  Various sensors are arranged in the image forming unit 10. Specifically, a paper sensor 61 (paper presence / absence detecting means) that detects the presence or absence of paper in the first paper feed tray 91, and paper sensors 62a to 62c that detect the presence or absence of paper in the paper feed trays 92a to 92c, It has. The sheet sensors 61 and 62a to 62c for detecting the sheet include a light emitting unit that emits light and a light receiving unit that detects the amount of light received. The presence or absence of is detected. Further, it detects that the sheet has changed from the presence to absence by changing the amount of received light and vice versa. The various sensors are not limited to optical sensors, and general sensors used for paper detection may be used.

[Electrical configuration of printer]
FIG. 3 is a block diagram schematically showing the electrical configuration of the printer 100.

  As shown in the figure, the printer 100 includes a control unit 30 including a CPU 31, a ROM 32, a RAM 33, an NVRAM 34, an ASIC 35, and a network interface 36. The control unit 30 is electrically connected to the image forming unit 10, the operation panel 40, and the like. The image forming unit 10 and the operation panel 40 are controlled by the control unit 30 and operate independently.

  The CPU 31 executes arithmetic operations for realizing various functions in the printer 100 such as a print job execution process described later, and is the center of control. The ROM 32 stores various control programs for controlling the printer 100, various settings, initial values, and the like. The RAM 33 is used as a work area from which various control programs are read or as a storage area for temporarily storing image data. An NVRAM (Non Volatile RAM) 34 is a non-volatile storage means and is used as a storage area for storing various settings or image data.

  The CPU 31 stores the processing results in the RAM 33 or the NVRAM 34 according to the control program read from the ROM 32 and signals sent from various sensors, and turns on the components of the printer 100 (for example, the lighting timing of the exposure apparatus constituting the process unit 50). The drive motors (not shown) of various rollers arranged in the transport path 11, transport paths 12a to 12c, and transport path 13 are controlled via the ASIC 35.

  The network interface 36 is connected to a network such as the Internet, and enables connection with an information processing apparatus such as a personal computer or a portable terminal device. Data communication with the information processing apparatus can be performed via the network interface 36.

[Printing operation]
Subsequently, the printing operation of the printer 100 will be described with attention paid to the switching of the paper feed tray. The printer 100 has a function of automatically switching a paper feed tray (hereinafter referred to as a paper feed target tray) that feeds paper between the paper feed trays 91 and 92a to 92c. In this automatic switching function, when it is detected that the paper feed target tray has become empty, it is automatically switched to another paper feed tray and printing is continued.

[Print job execution processing]
Hereinafter, the procedure of the print job execution process of the printer 100 that realizes the above-described printing operation will be described with reference to the flowcharts of FIGS. The print job execution process is repeatedly executed by the CPU 31 while the printer 100 is powered on. FIG. 4 is a flowchart illustrating print job execution processing according to the embodiment. FIG. 5 is a flowchart showing a priority change necessity determination process. FIG. 6 is a flowchart showing the priority changing process.

  First, it is determined whether a print job has been received via the network interface 36 (S101). If it is determined that a print job has not been received (S101: No), the process waits until a print job is received. If it is determined that a print job has been received (S101: Yes), a priority change necessity determination process is executed (S102). This priority change necessity determination process determines whether or not it is necessary to change the preset priority of the paper feed tray before the start of the print job, and performs execution control of the priority change process according to the determination. It is processing.

  The paper feed tray priority indicates the order of switching the paper feed target tray, and is stored in the NVRAM 34. During printing, according to the priority, when the high-priority paper feed tray becomes empty, the printer 100 operates to feed paper from the next high-priority paper feed tray.

  Further, the priority of the paper feed tray may be a default priority preset by the printer manufacturer, or may be changed by a user setting.

  When the CPU 31 starts the priority change necessity determination process shown in FIG. 5, it first obtains the priority information of the paper feed tray stored in the NVRAM 34 (S201).

  Next, based on the obtained paper feed tray priority information, the printer 100 determines whether or not to preferentially feed paper from the lower paper feed tray (S202). If it is determined that the paper feeding is not performed preferentially from the lower paper feeding tray (S202: No), it is set that the priority of the paper feeding tray needs to be changed (S205), and this priority change necessity judgment processing is performed. To return to the processing of FIG. Note that the setting that requires priority change is temporarily stored in the RAM 33.

  On the other hand, when the CPU 31 determines that the sheet feeding is preferentially performed from the lower sheet feeding tray (S202: Yes), that is, the fourth sheet feeding tray 92c has the highest priority, and the third sheet feeding tray 92b, When the priority is lowered in the order of the second paper feed tray 92a and the first paper feed tray 91, the CPU 31 among all the paper feed trays, That is, it is determined whether there is an empty paper feed tray (S203). Here, whether or not there is a sheet stored in the sheet feed tray is determined based on output signals of the sheet sensors 61 and 62a to 62c installed in each sheet feed tray.

  If it is determined that there is an empty paper feed tray (S203: Yes), it is set that the priority of the paper feed tray needs to be changed (S205), the priority change necessity determination process is terminated, and FIG. Return to the process. It should be noted that the setting for changing the priority of the paper feed tray is temporarily stored in the RAM 33.

  On the other hand, when it is determined that there is no empty paper feed tray, that is, when it is determined that there is paper in all the paper feed trays (S203: No), the priority of the paper feed tray is not required to be changed. (S204) This priority change necessity determination process is terminated, and the process returns to the process of FIG. Similarly, the setting that does not require changing the priority of the paper feed tray is temporarily stored in the RAM 33 as well.

  Next, in S103 (FIG. 4), the CPU 31 determines whether or not the priority needs to be changed based on the setting stored in the RAM 33 (S103). If the CPU 31 determines that the priority need not be changed (S103: No), the CPU 31 executes the print job according to the preset priority without changing the priority of the paper feed tray (S104). In other words, the highest priority paper feed tray is set as a paper feed target tray, and paper is transported from the paper feed target tray to execute a print job. After executing the print job, the process returns to S101.

  If the CPU 31 determines that the priority needs to be changed based on the setting stored in the RAM 33 (S103: Yes), the CPU 31 executes a priority change process (S105).

  As shown in FIG. 6, the priority changing process is started with the first paper feed tray 91 as the first execution target (S301), and the priority is initialized. The initialization of priority is to set the priority value set in the NVRAM 34 to unset. Note that the priority change process is performed in the order of the second paper feed tray 92a, the third paper feed tray 92b, and the fourth paper feed tray 92c by repeating the processes of S302 and S304.

  If the CPU 31 determines that the execution target is higher than the lowermost paper feed tray (fourth paper feed tray 92c) (S302: Yes), it is determined whether or not there is paper stored in the execution target paper feed tray. Judgment is made (S303).

  If it is determined that there is a sheet to be stored in the execution target paper feed tray (S303: Yes), the paper feed tray immediately below the execution target paper feed tray is set as the execution target (S304), and the process proceeds to S302. To do.

  On the other hand, if it is determined that there is no sheet to be stored in the execution target paper feed tray (S303: No), whether or not the execution target paper feed tray is the uppermost paper feed tray (first paper feed tray 91). Is determined (S305). If it is the uppermost paper feed tray (S305: Yes), that is, the first paper feed tray 91 is empty, so the priority of the first paper feed tray 91 is given the highest priority for the time being (S306). The priority change process is terminated and the process returns to the process of FIG.

  After determining that the execution target paper feed tray is not the uppermost paper feed tray (S305: No), the execution target paper feed tray is empty. In step S307, the priority of the selected paper feed tray is set as the highest priority (S308).

  After that, if there is a paper feed tray that has not yet been set with priority in the paper feed tray above the paper feed tray selected in S307 (S309: Yes), it is one higher than the paper feed tray selected in S307. A paper feed tray is selected, the next higher priority is set for the selected paper feed tray (S310), and the process proceeds to S309.

  If all the priority levels of the paper feed trays above the paper feed tray selected in S307 are set (S309: No), this priority change process is terminated and the process returns to the process of FIG.

  If the CPU 31 determines in S302 that the paper feed tray to be executed is the lowermost paper feed tray (S302: No), the process proceeds to S308.

Through the above priority change processing, the priority of the paper feed tray is set. The new priority is to sequentially feed the paper feed trays above the uppermost paper feed tray among the paper feed trays detected as having no paper. For example, when the second paper feed tray 92a and the fourth paper feed tray 92c are empty, even if there is paper in the third paper feed tray 92b, the priority is not set and the highest priority is given to the first paper feed tray 91. Priority is set. This is because if the second sheet feeding tray 92a is empty and the sheet is fed from the third tray 92b, the second sheet feeding tray 92a may be taken out during sheet feeding and a sheet jam may occur. Because. The paper feed tray set with the priority in this way becomes a target for switching the paper feed tray when the paper feed tray becomes empty during printing. On the other hand, in the above-described priority change process, no priority is set for the empty paper feed tray and the paper feed tray below the empty paper feed tray. Accordingly, when the paper in the paper feed tray becomes empty during printing, the paper feed tray for which priority is not set is not subject to switching.

  Returning to FIG. 4, the description will be continued. After the priority changing process S105, the paper feed tray having the highest priority is set as the paper feed target tray (S106). Next, it is determined whether or not there is a sheet in the uppermost sheet feed tray, that is, the first sheet feed tray 91 (S107). When it is determined that there is no sheet in the first sheet feed tray 91 (S107: No). Then, the printing is interrupted, and a state of waiting for paper replenishment is set (S108). In a state of waiting for paper replenishment, in order to notify the user to that effect, a display to the effect that paper is replenished to the first paper feed tray 91 may be displayed on the display unit 41.

  Thereafter, it is determined whether or not the paper supply to the first paper feed tray 91 is completed (S109). If the paper supply has not been completed (S109: No), the process waits until the paper supply is completed. Completion of paper replenishment can be determined, for example, by detecting that the output signal from the paper sensor 61 has changed from no paper to paper present.

  When the paper replenishment is completed (S109: Yes), after confirming that the first paper feed tray 91 is accommodated in the printer 100, the process proceeds to S105. Here, whether or not the first paper feed tray 91 is accommodated in the printer 100 may be confirmed based on an output signal of a sensor (not shown) for confirming the accommodation state of the first paper feed tray 91, for example.

  If it is determined that there is a sheet in the first sheet feed tray 91 (S107: Yes), the CPU 31 determines whether there is a sheet in the sheet to be fed (S110). If it is determined that the paper feed target tray is empty (S110: No), the paper feed target tray is switched to the paper feed tray having the next highest priority based on the above-described priority change processing (S114), and S111. Migrate to

  Here, the user may be informed that the sheet is replenished to the display unit 41 with respect to the empty sheet feeding tray. It is preferable to display that paper is replenished in order from the uppermost paper feed tray among the empty paper feed trays below the paper feed target tray. For example, when the first paper feed tray 91 is set as a paper feed target tray and the second paper feed tray 92a and the fourth paper feed tray 92c are empty, the second paper feed tray 92a. It is preferable to display on the display unit 41 that paper is replenished. When the replenishment of paper in the second paper feed tray 92a is completed, a display indicating that the paper is replenished in the fourth paper feed tray 92c may be displayed on the display unit 41.

  In the above priority changing process, no priority is set for the empty paper feed tray and the tray below the empty paper feed tray. Therefore, even if the paper in the lower paper feed tray than the uppermost paper feed tray is replenished among the empty paper feed trays lower than the paper supply target tray, the paper with no priority is set. Paper trays are not subject to switching.

  However, by displaying that paper is replenished in order from the uppermost paper feed tray among the empty paper feed trays below the paper feed target tray, the paper replenished in the processing of S111 and S105 described later is supplied. The paper tray can be a switching target.

  If there is paper in the paper feed target tray (S110: Yes), as described above, it is determined whether or not the paper replenishment to the empty paper feed tray immediately below that paper feed target tray is completed (S111). ). When the paper replenishment is completed (S111: Yes), the process proceeds to S105.

  One sheet of paper when replenishment of paper to an empty paper feed tray one lower than the paper feed target tray is not completed or when there is no empty paper feed tray below the paper feed target tray (S111: No) Printing of the image data for the corresponding portion is executed (S112). In other words, paper is fed from the paper feed target tray and image data is printed. Next, it is determined whether or not the print job is completed (S113). When the print job is not completed (S113: No), the process proceeds to S107. When the print job is completed (S113: Yes), the process proceeds to S101 and waits until a new print job is received.

[Effect of this embodiment]
As described above in detail, the printer 100 according to this embodiment includes four paper feeding units (a first paper feeding cassette 91, a second paper feeding tray 92a, a third paper feeding tray 92b, and a fourth paper feeding tray 92c). , Transport paths 11 and 12a to 12c from the respective paper feed trays to the transport path 13 are provided. Further, the transport paths 12a to 12c are configured to pass through an upper paper feed tray.

  In such a configuration, when there are a plurality of paper feed trays that can feed paper by executing the priority changing process, paper is fed from the lower paper feed tray. In other words, paper is emptied from the lower paper feed tray by preferentially feeding the lower paper feed tray. Therefore, it is possible to avoid the upper tray from becoming empty from the tray to be fed.

  With this configuration, the possibility that the upper paper feed tray is pulled out to replenish paper into the empty upper paper feed tray is reduced, and the occurrence of paper jam can be prevented. Note that since the paper is replenished to the lower paper feed tray from the paper feed target tray, even if the user pulls out the lower paper feed tray, the conveyance path is not blocked. It is possible to prevent the occurrence of paper jam due to the replenishment of paper.

  In addition, the printer 100 according to this embodiment includes a paper sensor 61 that detects the presence or absence of paper in the first paper feed tray 91 and paper sensors 62a to 62c that detect the presence or absence of paper in the paper feed trays 92a to 92c. When it is detected that there is no sheet stored in the sheet feeding tray, the sheet feeding is continued by switching to the sheet feeding tray above the sheet feeding tray. That is, during paper feeding, even if the paper feeding tray becomes empty, the upper paper feeding tray is automatically switched, so that printing can be continued.

  In addition, since it is possible to prevent the upper paper feed tray from becoming empty from the paper feed target tray, it is possible to prevent paper jamming. Since the paper is replenished to the lower lower paper feed tray, even if the user pulls out the lower paper feed tray, the conveyance path is not interrupted. It is possible to prevent the occurrence of paper jam due to.

  In addition, the printer 100 according to this embodiment includes a paper sensor 61 that detects the presence or absence of paper in the first paper feed tray 91 and paper sensors 62a to 62c that detect the presence or absence of paper in the paper feed trays 92a to 92c. When there are a plurality of empty paper feed trays, paper is fed from a paper feed tray above the uppermost paper feed tray among the plurality of paper feed trays. That is, by feeding paper from an upper paper feed tray above the uppermost paper feed tray among empty paper feed trays, it is possible to avoid emptying the paper feed tray above the paper feed target tray. Occurrence of paper jam due to paper replenishment to the tray can be prevented.

  In addition, the printer 100 according to the present exemplary embodiment sequentially feeds paper from the lower feed tray. That is, by feeding the lower feed tray preferentially, it is possible to avoid the upper feed tray from being emptied from the tray to be fed and to prevent the occurrence of paper jam due to the replenishment of the paper to the feed tray. Can be prevented.

In addition, when it is detected that there is no paper stored in the paper feed tray, the printer 100 according to the present embodiment removes the paper feed tray from the switching target and waits for replenishment, and the empty paper feed tray When it is detected that there is a sheet of paper, the paper feed tray is set as a switching target. That is, when paper is replenished to an empty paper feed tray, printing can be continued by switching to the replenished paper feed tray and feeding again.

  Further, the printer 100 according to the present embodiment can issue a warning prompting the user to replenish the recording medium in the paper supply tray waiting for replenishment, and issues warnings in order from the upper paper feed tray among the paper supply trays waiting for replenishment. . With this configuration, printing can be continued by prompting the user to replenish paper before all the paper feed trays are empty. In addition, since the warning means issues warnings in order from the upper paper tray among the paper supply trays waiting for replenishment, the paper is replenished while avoiding that the upper tray is empty from the target tray. The selected paper feed tray can be the target of switching. Thereby, it is possible to continue printing while preventing the occurrence of paper jam.

  Note that this embodiment is merely an example, and does not limit the present invention. Therefore, the present invention can naturally be improved and modified in various ways without departing from the gist thereof. For example, the present invention is not limited to a printer, and can be applied to any apparatus having a printing function such as a copying machine, a multifunction machine, and a FAX apparatus. The image forming method of the process unit is not limited to the electrophotographic method, and may be an ink jet method.

DESCRIPTION OF SYMBOLS 10 Image formation part 11, 12a-12c, 13 Conveyance path 30 Control part 41 Display part 61, 62a-62c Paper sensor 91 1st paper feed tray 92a 2nd paper feed tray 92b 3rd paper feed tray 92c 4th paper feed tray 100 printer

Claims (7)

Image forming means for printing an image on a recording medium;
A plurality of paper feed trays arranged above and below to accommodate the recording medium;
A printing pass for conveying the recording medium to the image forming means;
A first paper feed path for conveying the recording medium from the uppermost paper feed tray to the print path;
A second paper feed path for transporting the recording medium discharged from the paper feed tray excluding the uppermost paper feed tray to the print path via the paper feed tray above the paper feed tray;
A paper feeding means for feeding the recording medium housed in any of the plurality of paper feeding trays;
In the case where there are a plurality of paper feeding trays capable of feeding toward the image forming means, the paper feeding means feeds paper from a lower paper feeding tray among the plurality of paper feeding trays. Forming equipment.
A paper presence / absence detecting means for detecting the presence / absence of the recording medium stored in the paper feed tray;
The paper feed means is a paper feed tray above the paper feed tray when the paper presence / absence detection means detects that there is no recording medium contained in the paper feed tray being fed. The image forming apparatus according to claim 1, wherein the sheet feeding is continued by switching to.
A paper presence / absence detecting means for detecting the presence / absence of the recording medium stored in the paper feed tray;
When the paper presence / absence detection means detects that the recording medium is not present in the plurality of paper feeding trays, the paper feeding means is the uppermost feeding tray among the paper feeding trays without the plurality of recording media. The image forming apparatus according to claim 1, wherein paper is fed from a paper feed tray above the paper tray.
The image forming apparatus according to claim 1, wherein the paper feeding unit feeds paper in order from the lower paper feed tray.
The paper feeding means, when it is detected by the paper presence / absence detecting means that there is no recording medium stored in the paper feeding tray, removes the paper feeding tray from the switching target and sets it as a waiting for replenishment,
5. The image forming apparatus according to claim 2, wherein when the recording medium is detected by the sheet presence / absence detection unit, the sheet feeding tray is set as a switching target.
Warning means for issuing a warning prompting replenishment of the recording medium to the paper supply tray waiting for replenishment;
The image forming apparatus according to claim 5, wherein the warning unit issues the warning in order from an upper paper feed tray among the paper supply trays waiting for replenishment.
Image forming means for printing an image on a recording medium;
A plurality of paper feed trays arranged above and below to accommodate the recording medium;
A main paper feed path for transporting the recording medium discharged from the paper feed tray to the image forming unit;
A sub paper feed path provided in a paper feed tray other than the lowermost paper feed tray and for guiding the recording medium discharged from the lower paper feed tray of the paper feed tray toward the main paper feed path When,
A sheet feeding unit configured to feed the recording medium accommodated in any of the plurality of sheet feeding trays;
The image forming apparatus, wherein the sheet feeding unit feeds paper from a lower sheet feeding tray when there are a plurality of sheet feeding trays capable of feeding toward the image forming unit.